def alternate_1():
  """Internal call DN1 to  DN2, DN2 initate cons. call to DN3, DN2 alternate call"""
  SipPhone1.MakeCall(DN2)
  SipPhone2.AnswerCall()
  SipPhone2.InitiateTransfer(DN3)
  SipPhone2.AlternateCall()
  SipPhone1.ReleaseCall()
  SipPhone2.RetrieveCall()
  SipPhone2.ReleaseCall()
  

def alternate_2():
  """Internal call DN1 to  DN2, DN2 initate cons. call to DN3, DN3 answer, DN2 alternate call"""
  SipPhone1.MakeCall(DN2)
  SipPhone2.AnswerCall()
  SipPhone2.InitiateTransfer(DN3)
  SipPhone3.AnswerCall()
  SipPhone2.AlternateCall()
  SipPhone3.ReleaseCall()
  SipPhone1.ReleaseCall()


def alternate_3():
  """ DN1 call to DN2,  DN2 hold, DN2 internal  call to DN3, DN2 alternate call"""
  SipPhone1.MakeCall(DN2)
  SipPhone2.AnswerCall()
  SipPhone2.HoldCall()
  SipPhone2.MakeCall(DN3)
  SipPhone2.AlternateCall()
  SipPhone1.ReleaseCall()
  SipPhone2.RetrieveCall()
  SipPhone2.ReleaseCall()   
  
def alternate_4():
  """ DN1 call to DN2,  DN2 hold, DN2 internal  call to DN3, DN3 answer, DN2 alternate call"""
  SipPhone1.MakeCall(DN2)
  SipPhone2.AnswerCall()
  SipPhone2.HoldCall()
  SipPhone2.MakeCall(DN3)
  SipPhone3.AnswerCall()
  SipPhone2.AlternateCall()
  SipPhone3.ReleaseCall()  
  SipPhone1.ReleaseCall()